WO 2006/050723 A1 discloses a tower part for a wind turbine having an aperture suitable for installing a door. The tower part has a substantially uniform thickness and is thicker than the thickness of a wall segment of the tower to which the tower part having the aperture is mounted.
WO 03/036085 A1 discloses a structural unit for constructing a tower of a wind turbine, wherein the structural unit has a through opening for accommodating a door and wherein the structural unit is at least partially formed as cast part.
There may be a need for a wall section for a wind turbine tower having an opening suitable for accommodating a door which at the same time provides sufficient structural rigidity and stiffness in order not to reduce the stiffness of the wind turbine tower, when the wall section is used as a part of a bottom part of the wind turbine tower. Further, there may be a need for a wall section for a wind turbine tower having a reduced weight but providing a sufficient structural rigidity and strength to be suitable as a portion of a wind turbine tower shell.